Hi Jeffy,
On Tue, Jun 13, 2017 at 01:25:41PM +0800, Jeffy Chen wrote:
> Support using "cs-gpios" property to specify cs gpios.
>
> Signed-off-by: Jeffy Chen <[email protected]>
> 1/ request cs gpios in probe for better error handling
> 2/ use gpiod* function
> (suggested by Heiko Stuebner)
>
> 3/ split dt-binding changes to new patch
> (suggested by Shawn Lin & Heiko Stuebner)
>
> ---
>
> Changes in v2: None
>
> drivers/spi/spi-rockchip.c | 30 +++++++++++++++++++++++++++++-
> 1 file changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
> index bab9b13..ad8997b 100644
> --- a/drivers/spi/spi-rockchip.c
> +++ b/drivers/spi/spi-rockchip.c
> @@ -16,7 +16,7 @@
> #include <linux/clk.h>
> #include <linux/dmaengine.h>
> #include <linux/module.h>
> -#include <linux/of.h>
> +#include <linux/of_gpio.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
> #include <linux/spi/spi.h>
> @@ -663,6 +663,27 @@ static bool rockchip_spi_can_dma(struct spi_master
> *master,
> return (xfer->len > rs->fifo_len);
> }
>
> +static int rockchip_spi_setup_cs_gpios(struct device *dev)
> +{
> + struct device_node *np = dev->of_node;
> + struct gpio_desc *cs_gpio;
> + int i, nb;
> +
> + if (!np)
> + return 0;
> +
> + nb = of_gpio_named_count(np, "cs-gpios");
> + for (i = 0; i < nb; i++) {
> + /* We support both GPIO CS and HW CS */
> + cs_gpio = devm_gpiod_get_index_optional(dev, "cs",
> + i, GPIOD_ASIS);
> + if (IS_ERR(cs_gpio))
> + return PTR_ERR(cs_gpio);
I'm a bit confused why you need this function at all. You aren't using
the references that you're grabbing here, so essentially this is just
error-checking.
Are you doing anything here that isn't covered in
of_spi_register_master()?
> + }
> +
> + return 0;
> +}
> +
> static int rockchip_spi_probe(struct platform_device *pdev)
> {
> int ret = 0;
> @@ -749,6 +770,7 @@ static int rockchip_spi_probe(struct platform_device
> *pdev)
> master->transfer_one = rockchip_spi_transfer_one;
> master->max_transfer_size = rockchip_spi_max_transfer_size;
> master->handle_err = rockchip_spi_handle_err;
> + master->flags = SPI_MASTER_GPIO_SS;
I'm curious, do you actually need to assert both the HW and GPIO CS?
Brian
>
> rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
> if (IS_ERR(rs->dma_tx.ch)) {
> @@ -783,6 +805,12 @@ static int rockchip_spi_probe(struct platform_device
> *pdev)
> master->dma_rx = rs->dma_rx.ch;
> }
>
> + ret = rockchip_spi_setup_cs_gpios(&pdev->dev);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to setup cs gpios\n");
> + goto err_free_dma_rx;
> + }
> +
> ret = devm_spi_register_master(&pdev->dev, master);
> if (ret) {
> dev_err(&pdev->dev, "Failed to register master\n");
> --
> 2.1.4
>
>
